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authorK. Y. Srinivasan <kys@microsoft.com>2012-07-24 16:11:58 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-08-13 18:42:25 -0700
commit83ba0c4f3f317270dae5597d8044b795d119914c (patch)
tree1db3640642f68f5e57de0404a8e7a47ac2bbc899 /drivers/hv
parent0d7614f09c1ebdbaa1599a5aba7593f147bf96ee (diff)
Drivers: hv: Cleanup the guest ID computation
The current guest ID string in use in vmbus driver does not conform to the MSFT guidelines on guest ID. MSFT currently does not specify Linux specific guidelines. MSFT however has plans to publish Linux specific guidelines. This implementation conforms to the yet unpublished Linux specific guidelines for guest ID. This implementation also broadly conforms to the current guidelines as well. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Cc: Bjørn Mork <bjorn@mork.no> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv')
-rw-r--r--drivers/hv/hv.c9
-rw-r--r--drivers/hv/hyperv_vmbus.h47
2 files changed, 49 insertions, 7 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 86f8885aeb45..771e24f2981d 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -26,6 +26,7 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/hyperv.h>
+#include <linux/version.h>
#include <asm/hyperv.h>
#include "hyperv_vmbus.h"
@@ -164,9 +165,11 @@ int hv_init(void)
max_leaf = query_hypervisor_info();
- /* Write our OS info */
- wrmsrl(HV_X64_MSR_GUEST_OS_ID, HV_LINUX_GUEST_ID);
- hv_context.guestid = HV_LINUX_GUEST_ID;
+ /*
+ * Write our OS ID.
+ */
+ hv_context.guestid = generate_guest_id(0, LINUX_VERSION_CODE, 0);
+ wrmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
/* See if the hypercall page is already set */
rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 0614ff3a7d7e..d8d1fadb398a 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -410,10 +410,49 @@ enum {
#define HV_PRESENT_BIT 0x80000000
-#define HV_LINUX_GUEST_ID_LO 0x00000000
-#define HV_LINUX_GUEST_ID_HI 2976579765
-#define HV_LINUX_GUEST_ID (((u64)HV_LINUX_GUEST_ID_HI << 32) | \
- HV_LINUX_GUEST_ID_LO)
+/*
+ * The guest OS needs to register the guest ID with the hypervisor.
+ * The guest ID is a 64 bit entity and the structure of this ID is
+ * specified in the Hyper-V specification:
+ *
+ * http://msdn.microsoft.com/en-us/library/windows/hardware/ff542653%28v=vs.85%29.aspx
+ *
+ * While the current guideline does not specify how Linux guest ID(s)
+ * need to be generated, our plan is to publish the guidelines for
+ * Linux and other guest operating systems that currently are hosted
+ * on Hyper-V. The implementation here conforms to this yet
+ * unpublished guidelines.
+ *
+ *
+ * Bit(s)
+ * 63 - Indicates if the OS is Open Source or not; 1 is Open Source
+ * 62:56 - Os Type; Linux is 0x100
+ * 55:48 - Distro specific identification
+ * 47:16 - Linux kernel version number
+ * 15:0 - Distro specific identification
+ *
+ *
+ */
+
+#define HV_LINUX_VENDOR_ID 0x8100
+
+/*
+ * Generate the guest ID based on the guideline described above.
+ */
+
+static inline __u64 generate_guest_id(__u8 d_info1, __u32 kernel_version,
+ __u16 d_info2)
+{
+ __u64 guest_id = 0;
+
+ guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
+ guest_id |= (((__u64)(d_info1)) << 48);
+ guest_id |= (((__u64)(kernel_version)) << 16);
+ guest_id |= ((__u64)(d_info2));
+
+ return guest_id;
+}
+
#define HV_CPU_POWER_MANAGEMENT (1 << 0)
#define HV_RECOMMENDATIONS_MAX 4

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